Device for the beam shaping of an incident laser beam

Patent metadata

Field	Value
Publication number	US-12566334-B2
Application number	US-202418409855-A
Country	US
Kind code	B2
Filing date	Jan 11, 2024
Priority date	Jul 13, 2021
Publication date	Mar 3, 2026
Grant date	Mar 3, 2026

Abstract

A device for beam shaping of a laser beam includes a prism, a polarization rotator, and a thin-film polarizer. The prism is configured to split an incident laser beam into a first beam half and a second beam half. The first beam half is input coupled into the prism. The first beam half enters the prism at a first incidence side arranged at the Brewster angle vis-à-vis the incident laser beam. The first beam half input coupled into the prism is output coupled from the prism at an exit side of the prism at the Brewster angle. The thin-film polarizer is traversed by the first beam half output coupled from the prism. The polarization rotator rotates a polarization of the second beam half. The second beam half is reflected by the thin-film polarizer. The thin-film polarizer superimposes the first beam half and the second beam half.

First claim

The invention claimed is:

1 . A device for beam shaping of a laser beam, the device comprising a prism, a polarization rotator, and a thin-film polarizer,
the prism being arranged such that it splits an incident laser beam into a first beam half and a second beam half, with at least the first beam half being input coupled into the prism; the first beam half entering the prism at a first incidence side, with the prism being configured such that the first incidence side is arranged at the Brewster angle vis-à-vis the incident laser beam, the prism being configured such that the first beam half input coupled into the prism is output coupled from the prism at an exit side of the prism, with the first beam half being output coupled from the prism at the Brewster angle, with the thin-film polarizer being arranged such that it is traversed by the first beam half output coupled from the prism, the polarization rotator being arranged such that it is traversed by the second beam half and rotates a polarization of the second beam half, and the second beam half being guided such that it is reflected by the thin-film polarizer, and the thin-film polarizer superimposes the first beam half and the second beam half.

2 . The device as claimed in claim 1 , wherein the first exit side is at the Brewster angle with respect to the first beam half which is input coupled into the prism and incident on the first exit side,
with the thin-film polarizer being arranged such that it is traversed at the Brewster angle by the first beam half output coupled from the prism.

3 . The device as claimed in claim 1 , wherein the incident laser beam is p-polarized.

4 . The device as claimed in claim 1 , wherein the polarization rotator is attached to the prism and/or wherein the polarization rotator is a half-wave plate.

5 . The device as claimed in claim 1 , wherein the polarization rotator is configured such that the polarization of the second beam half is rotated through 90° into an s-polarization.

6 . The device as claimed in claim 1 , wherein the prism is configured such that at least one of the first beam half and the second beam half undergoes total-internal reflection within the prism.

7 . The device as claimed in claim 1 , further comprising at least one mirror, the at least one mirror reflecting the second beam half, following the traversal of the polarization rotator, at the thin-film polarizer.

8 . The device as claimed in claim 7 , wherein the at least one mirror and the prism are preassembled on a common base plate.

9 . The device as claimed in claim 1 , wherein the prism is arranged and configured such that the second beam half is input coupled into the prism at a second incidence side, the second incidence side being arranged at the Brewster angle vis-à-vis the incident laser beam.

10 . The device as claimed in claim 9 , wherein the prism is configured such that the second beam half is output coupled from the prism at a second exit side, the second exit side being arranged such that the second beam half is incident on the second exit side at the Brewster angle.

11 . The device as claimed in claim 10 , wherein the polarization rotator is arranged such that the second beam half output coupled from the prism traverses the polarization rotator.

12 . The device as claimed in claim 1 , wherein the second beam half does not enter the prism.

13 . The device as claimed in claim 12 , wherein the thin-film polarizer on the first exit side of the prism is realized by an optical coating.

14 . The device as claimed in claim 12 , wherein the prism is a Dove prism.

15 . A method for the beam shaping of a laser beam by using a device, the device comprising a prism, a polarization rotator, and a thin-film polarizer, the method comprising:
dividing an incident laser beam into a first beam half and a second beam half by striking the incident laser beam on the prism; causing the first beam half to be incident on a first entrance side of the prism at the Brewster angle, wherein the first beam half enters the prism, traverses the prism, and exits the prism at the Brewster angle, and wherein, following the traversal of the prism, the first beam half has a parallel offset from the incident laser beam; following the exit from the prism, causing the first beam half to traverse the thin-film polarizer; rotating a polarization of the second beam half by using the polarization rotator; deflecting the second beam half in a direction of the thin-film polarizer by refraction and/or reflection; reflecting the second beam half by using the thin-film polarizer; and superimposing the first beam half and the second beam half congruently downstream of the thin-film polarizer in a beam direction.

Assignees

• Trumpf Laser Gmbh
• Trumpf Photonics Inc

Inventors

• Rataj Thomas
• Irmler Lukas
• Killi Alexander
• Ried Steffen
• Wieschendorf Christoph

Classifications

• G02B27/0905

  Dividing and/or superposing multiple light beams · CPC title

• G02B27/286

  for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34) · CPC title

• G02B27/0972

  Prisms (prisms per se G02B5/04) · CPC title

• G02B27/0916 Primary

  Adapting the beam shape of a semiconductor light source such as a laser diode or an LED, e.g. for efficiently coupling into optical fibers (coupling into light guides using intermediate optical elements G02B6/4204; details of lighting devices in general F21V) · CPC title

• G02B27/0927 Primary

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title